From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 447E23858D28; Sat, 6 May 2023 15:19:55 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 447E23858D28 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1683386395; bh=az8JlqlW4PepgiWi7Vg6FyohIEVLKLKtgKhzEgErHFY=; h=From:To:Subject:Date:From; b=jLqWExypHiTa+6NWPNzXHQq2w3XLCf8EDDZ2UVvHw8pXqOHZgtFf8szbWtLxrS8AE +SyNHGAgtmi5egYKfIhT4P18oTlmbhGA0NNTa4SxuOPU884F2NZfLwzFGHjHiGxfQx tvzfzYKwx5do8XWZ/OXIl2X/NU0Nx28UfVvKnhFI= From: "jonathan.poelen at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/109757] New: Conversion from lvalue to rvalue without error Date: Sat, 06 May 2023 15:19:54 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Version: 12.2.1 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: jonathan.poelen at gmail dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109757 Bug ID: 109757 Summary: Conversion from lvalue to rvalue without error Product: gcc Version: 12.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: jonathan.poelen at gmail dot com Target Milestone: --- GCC 12.2.1 $ cat test.cpp void foo(int&&) {} int main() { using T =3D int&&; int x =3D 0; T{x}; // ok -> should be error foo(T{x}); // ok -> should be error //T r{x}; // nok -> is good } $ g++ test.cpp No error, there should be a 2 errors. $ g++ test.cpp -v -save-temps Using built-in specs. COLLECT_GCC=3Dg++ COLLECT_LTO_WRAPPER=3D/usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /build/gcc/src/gcc/configure --enable-languages=3Dc,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-boots= trap --prefix=3D/usr --libdir=3D/usr/lib --libexecdir=3D/usr/lib --mandir=3D/usr= /share/man --infodir=3D/usr/share/info --with-bugurl=3Dhttps://bugs.archlinux.org/ --with-build-config=3Dbootstrap-lto --with-linker-hash-style=3Dgnu --with-system-zlib --enable-__cxa_atexit --enable-cet=3Dauto --enable-checking=3Drelease --enable-clocale=3Dgnu --enable-default-pie --enable-default-ssp --enable-gnu-indirect-function --enable-gnu-unique-obj= ect --enable-libstdcxx-backtrace --enable-link-serialization=3D1 --enable-linker-build-id --enable-lto --enable-multilib --enable-plugin --enable-shared --enable-threads=3Dposix --disable-libssp --disable-libstdc= xx-pch --disable-werror Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 12.2.1 20230201 (GCC)=20 COLLECT_GCC_OPTIONS=3D'-v' '-save-temps' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' '-dumpdir' 'a-' /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/cc1plus -E -quiet -v -D_GNU_SOURCE test.cpp -mtune=3Dgeneric -march=3Dx86-64 -fpch-preprocess -o a-test.ii ignoring nonexistent directory "/usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/../../../../x86_64-pc-linux-gnu/in= clude" #include "..." search starts here: #include <...> search starts here: /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/../../../../include/c++/12.2.1 /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/../../../../include/c++/12.2.1/x86_= 64-pc-linux-gnu /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/../../../../include/c++/12.2.1/back= ward /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/include /usr/local/include /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/include-fixed /usr/include End of search list. COLLECT_GCC_OPTIONS=3D'-v' '-save-temps' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' '-dumpdir' 'a-' /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/cc1plus -fpreprocessed a-test.ii -quiet -dumpdir a- -dumpbase test.cpp -dumpbase-ext .cpp -mtune=3Dgeneric -march=3Dx86-64 -version -o a-test.s GNU C++17 (GCC) version 12.2.1 20230201 (x86_64-pc-linux-gnu) compiled by GNU C version 12.2.1 20230201, GMP version 6.2.1, MPFR version 4.2.0, MPC version 1.3.1, isl version isl-0.25-GMP GGC heuristics: --param ggc-min-expand=3D100 --param ggc-min-heapsize=3D131= 072 GNU C++17 (GCC) version 12.2.1 20230201 (x86_64-pc-linux-gnu) compiled by GNU C version 12.2.1 20230201, GMP version 6.2.1, MPFR version 4.2.0, MPC version 1.3.1, isl version isl-0.25-GMP GGC heuristics: --param ggc-min-expand=3D100 --param ggc-min-heapsize=3D131= 072 Compiler executable checksum: ab2adc4aa87e9c5b6e6cb24c55e663d5 COLLECT_GCC_OPTIONS=3D'-v' '-save-temps' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' '-dumpdir' 'a-' as -v --64 -o a-test.o a-test.s GNU assembler version 2.40 (x86_64-pc-linux-gnu) using BFD version (GNU Binutils) 2.40 COMPILER_PATH=3D/usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/:/usr/lib/gcc/x86_6= 4-pc-linux-gnu/12.2.1/:/usr/lib/gcc/x86_64-pc-linux-gnu/:/usr/lib/gcc/x86_6= 4-pc-linux-gnu/12.2.1/:/usr/lib/gcc/x86_64-pc-linux-gnu/ LIBRARY_PATH=3D/usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/:/usr/lib/gcc/x86_64= -pc-linux-gnu/12.2.1/../../../../lib/:/lib/../lib/:/usr/lib/../lib/:/usr/li= b/gcc/x86_64-pc-linux-gnu/12.2.1/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS=3D'-v' '-save-temps' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' '-dumpdir' 'a.' /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/collect2 -plugin /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/liblto_plugin.so -plugin-opt=3D/usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/lto-wrapper -plugin-opt=3D-fresolution=3Da.res -plugin-opt=3D-pass-through=3D-lgcc_s -plugin-opt=3D-pass-through=3D-lgcc -plugin-opt=3D-pass-through=3D-lc -plugin-opt=3D-pass-through=3D-lgcc_s -plugin-opt=3D-pass-through=3D-lgcc -= -build-id --eh-frame-hdr --hash-style=3Dgnu -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -pie /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/../../../../lib/Scrt1.o /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/../../../../lib/crti.o /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/crtbeginS.o -L/usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1 -L/usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/../../../../lib -L/lib/../lib -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/../../.. a-test= .o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/crtendS.o /usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/../../../../lib/crtn.o COLLECT_GCC_OPTIONS=3D'-v' '-save-temps' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' '-dumpdir' 'a.' Up to at least 8.5, the code compiles. With MSVC too. Does not compile with clang: https://godbolt.org/z/o96j5b8oc=